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Microsatellite Instability Analysis

Test Number 570149
Test number copied
CPT

81301; 88381

To be determined. Updates will be made when available.

81301; 88381
Synonyms
  • Colorectal Cancer Screening
  • Hereditary Nonpolyposis Colorectal Cancer, Screening
  • Mismatch Repair Defect
  • Replication Repair (RER)
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  • Updated on 02/17/2025

Test Details

Methodology

Multiplex polymerase chain reaction (PCR); capillary electrophoresis

Result Turnaround Time

10 - 14 days

Turnaround time is defined as the usual number of days from the date of pickup of a specimen for testing to when the result is released to the ordering provider. In some cases, additional time should be allowed for additional confirmatory or additional reflex tests. Testing schedules may vary.

Related Information

Use

This test is used to identify tumors with microsatellite instability. High-frequency microsatellite instability (MSI-H) is associated with Lynch syndrome, but it is also found in 15% to 20% of sporadic colorectal and endometrial cancers. Lynch syndrome is an autosomal-dominant inherited cancer syndrome that predisposes to colorectal, endometrial, gastric, ovarian, upper urinary tract and other cancers. MSI-H status may enhance the likelihood of tumor responsiveness to immune checkpoint inhibitor therapy.

Special Instructions

This assay needs both (1) DNA prepared from FFPE (formalin-fixed and paraffin-embedded) tumor tissue and (2) matched normal tissue (FFPE or blood). Please provide a copy of the pathology report. This test will be delayed if the pathology report is not received. Please direct any questions regarding this test to customer service at 800-345-4363.

Limitations

MSI-H is a marker of underlying DNA mismatch repair defect but does not define specific gene mutations responsible for cancers. If direct testing for gene mutations responsible for Lynch syndrome is desired, please call customer service at 800-345-4363 for more information. This assay can detect 8% to 12% of mutant in a background of wild-type genomic DNA.

This test was developed and its performance characteristics determined by Labcorp. It has not been cleared or approved by the Food and Drug Administration.

Specimen Requirements

Specimen

One paraffin-embedded tumor and either whole blood or paraffin-embedded normal tissue

Volume

Eight unstained slides at 5 μM and one matching H&E slide or FFPE tissue block or 3-5 mL whole blood

Minimum Volume

Samples with ≥4 mm² tumor and normal tissue surface area and ≥50% tumor content are preferred; 3 mL whole blood

Container

FFPE tissue block or slides, lavender-top (EDTA) tube or green-top (sodium heparin) tube, tan-top (K2-EDTA) tube or pink-top (K2-EDTA) tube

Storage Instructions

Blocks and slides at room temperature; whole blood at 2°C to 8°C

Causes for Rejection

Tumor block containing insufficient tumor tissue or no tumor; broken or stained slides. 

Whole blood: Contaminated specimen; frozen whole blood received; leaking tube; clotted blood; hemolysis; specimen containing suspicious foreign material; quantity not sufficient for analysis

References

NCCN Clinical Practice Guidelines in Oncology: Genetic/Familial High-Risk Assessment: Colorectal. Version 2.2015.
 
Promega Technical Manual. MSI Analysis System v1.2. Oct 2012.
 
US Food and Drug Administration. Hematology/Oncology (Cancer) Approvals & Safety Notifications. FDA website: https://www.fda.gov/drugs/resources-information-approved-drugs/hematologyoncology-cancer-approvals-safety-notifications. Accessed April 2020.

LOINC® Map

Order Code Order Code Name Order Loinc Result Code Result Code Name UofM Result LOINC
570149 Microsatellite Instability 570150 Referring Physician 18781-5
570149 Microsatellite Instability 570151 Referring Physician Phone N/A
570149 Microsatellite Instability 570152 Treating Physician 18781-5
570149 Microsatellite Instability 570153 Treating Physician Phone N/A
570149 Microsatellite Instability 570154 Body Site 39111-0
570149 Microsatellite Instability 570155 Client Specimen ID N/A
570149 Microsatellite Instability 570156 Specimen(s) Received N/A
570149 Microsatellite Instability 570157 Clinical Data: 55752-0
570149 Microsatellite Instability 570158 Testing Performed N/A
570149 Microsatellite Instability 570159 Results 43368-0
570149 Microsatellite Instability 570160 Interpretation: 50595-8
570149 Microsatellite Instability 570161 Comments: 22638-1
570149 Microsatellite Instability 570162 Methodology 49549-9
570149 Microsatellite Instability 570163 References: N/A
570149 Microsatellite Instability 570164 Electronically Signed by 19139-5
570149 Microsatellite Instability 570165 Reported By: N/A
570149 Microsatellite Instability 570166 Disclaimer N/A
570149 Microsatellite Instability 570167 PDF 50398-7
570149 Microsatellite Instability 570185 Bill Code Entry Hold N/A
Order Code570149
Order Code NameMicrosatellite Instability
Order Loinc
Result Code570150
Result Code NameReferring Physician
UofM
Result LOINC18781-5
Order Code570149
Order Code NameMicrosatellite Instability
Order Loinc
Result Code570151
Result Code NameReferring Physician Phone
UofM
Result LOINCN/A
Order Code570149
Order Code NameMicrosatellite Instability
Order Loinc
Result Code570152
Result Code NameTreating Physician
UofM
Result LOINC18781-5
Order Code570149
Order Code NameMicrosatellite Instability
Order Loinc
Result Code570153
Result Code NameTreating Physician Phone
UofM
Result LOINCN/A
Order Code570149
Order Code NameMicrosatellite Instability
Order Loinc
Result Code570154
Result Code NameBody Site
UofM
Result LOINC39111-0
Order Code570149
Order Code NameMicrosatellite Instability
Order Loinc
Result Code570155
Result Code NameClient Specimen ID
UofM
Result LOINCN/A
Order Code570149
Order Code NameMicrosatellite Instability
Order Loinc
Result Code570156
Result Code NameSpecimen(s) Received
UofM
Result LOINCN/A
Order Code570149
Order Code NameMicrosatellite Instability
Order Loinc
Result Code570157
Result Code NameClinical Data:
UofM
Result LOINC55752-0
Order Code570149
Order Code NameMicrosatellite Instability
Order Loinc
Result Code570158
Result Code NameTesting Performed
UofM
Result LOINCN/A
Order Code570149
Order Code NameMicrosatellite Instability
Order Loinc
Result Code570159
Result Code NameResults
UofM
Result LOINC43368-0
Order Code570149
Order Code NameMicrosatellite Instability
Order Loinc
Result Code570160
Result Code NameInterpretation:
UofM
Result LOINC50595-8
Order Code570149
Order Code NameMicrosatellite Instability
Order Loinc
Result Code570161
Result Code NameComments:
UofM
Result LOINC22638-1
Order Code570149
Order Code NameMicrosatellite Instability
Order Loinc
Result Code570162
Result Code NameMethodology
UofM
Result LOINC49549-9
Order Code570149
Order Code NameMicrosatellite Instability
Order Loinc
Result Code570163
Result Code NameReferences:
UofM
Result LOINCN/A
Order Code570149
Order Code NameMicrosatellite Instability
Order Loinc
Result Code570164
Result Code NameElectronically Signed by
UofM
Result LOINC19139-5
Order Code570149
Order Code NameMicrosatellite Instability
Order Loinc
Result Code570165
Result Code NameReported By:
UofM
Result LOINCN/A
Order Code570149
Order Code NameMicrosatellite Instability
Order Loinc
Result Code570166
Result Code NameDisclaimer
UofM
Result LOINCN/A
Order Code570149
Order Code NameMicrosatellite Instability
Order Loinc
Result Code570167
Result Code NamePDF
UofM
Result LOINC50398-7
Order Code570149
Order Code NameMicrosatellite Instability
Order Loinc
Result Code570185
Result Code NameBill Code Entry Hold
UofM
Result LOINCN/A
Reflex Table for Results
Order Code Order Name Result Code Result Name UofM Result LOINC
Reflex 1 057149 Microsatellite Instability (B) 000000 Results Pending
Reflex 1
Order Code057149
Order NameMicrosatellite Instability (B)
Result Code000000
Result NameResults
UofM
Result LOINCPending
Reflex Table for Results
Order Code Order Name Result Code Result Name UofM Result LOINC
Reflex 1 057149 Microsatellite Instability (B) 000000 Results Pending
Reflex 1
Order Code057149
Order NameMicrosatellite Instability (B)
Result Code000000
Result NameResults
UofM
Result LOINCPending
Reflex Table for Results
Order Code Order Name Result Code Result Name UofM Result LOINC
Reflex 1 057149 Microsatellite Instability (B) 000000 Results Pending
Reflex 1
Order Code057149
Order NameMicrosatellite Instability (B)
Result Code000000
Result NameResults
UofM
Result LOINCPending
Reflex Table for Results
Order Code Order Name Result Code Result Name UofM Result LOINC
Reflex 1 057149 Microsatellite Instability (B) 000000 Results Pending
Reflex 1
Order Code057149
Order NameMicrosatellite Instability (B)
Result Code000000
Result NameResults
UofM
Result LOINCPending
Reflex Table for Results
Order Code Order Name Result Code Result Name UofM Result LOINC
Reflex 1 057149 Microsatellite Instability (B) 000000 Results Pending
Reflex 1
Order Code057149
Order NameMicrosatellite Instability (B)
Result Code000000
Result NameResults
UofM
Result LOINCPending
Reflex Table for Results
Order Code Order Name Result Code Result Name UofM Result LOINC
Reflex 1 057149 Microsatellite Instability (B) 000000 PDF 11526-1
Reflex 1
Order Code057149
Order NameMicrosatellite Instability (B)
Result Code000000
Result NamePDF
UofM
Result LOINC11526-1